1*5246Sroot /* tcp_var.h 4.13 81/12/12 */ 24808Swnj 34808Swnj /* 44808Swnj * Kernel variables for tcp. 54808Swnj */ 64808Swnj 74808Swnj /* 85166Swnj * Tcp control block, one per tcp; fields: 94808Swnj */ 104881Swnj struct tcpcb { 115076Swnj struct tcpiphdr *seg_next; /* sequencing queue */ 125076Swnj struct tcpiphdr *seg_prev; 13*5246Sroot short t_state; /* state of this connection */ 145092Swnj short t_timer[TCPT_NTIMERS]; /* tcp timers */ 155166Swnj short t_rxtshift; /* log(2) of rexmt exp. backoff */ 165092Swnj struct mbuf *t_tcpopt; /* tcp options */ 175092Swnj struct mbuf *t_ipopt; /* ip options */ 185092Swnj short t_maxseg; /* maximum segment size */ 19*5246Sroot char t_force; /* 1 if forcing out a byte */ 205067Swnj u_char t_flags; 215092Swnj #define TF_ACKNOW 0x01 /* ack peer immediately */ 225092Swnj #define TF_DELACK 0x02 /* ack, but try to delay it */ 235092Swnj #define TF_PUSH 0x04 /* push mode */ 245092Swnj #define TF_URG 0x08 /* urgent mode */ 255166Swnj #define TF_DONTKEEP 0x10 /* don't use keep-alives */ 264881Swnj struct tcpiphdr *t_template; /* skeletal packet for transmit */ 275067Swnj struct inpcb *t_inpcb; /* back pointer to internet pcb */ 284808Swnj /* 295067Swnj * The following fields are used as in the protocol specification. 305067Swnj * See RFC783, Dec. 1981, page 21. 314808Swnj */ 325067Swnj /* send sequence variables */ 335067Swnj tcp_seq snd_una; /* send unacknowledged */ 345067Swnj tcp_seq snd_nxt; /* send next */ 355067Swnj tcp_seq snd_up; /* send urgent pointer */ 365067Swnj tcp_seq snd_wl1; /* window update seg seq number */ 375067Swnj tcp_seq snd_wl2; /* window update seg ack number */ 385067Swnj tcp_seq iss; /* initial send sequence number */ 39*5246Sroot u_short snd_wnd; /* send window */ 405067Swnj /* receive sequence variables */ 41*5246Sroot short rcv_wnd; /* receive window */ 425067Swnj tcp_seq rcv_nxt; /* receive next */ 435067Swnj tcp_seq rcv_up; /* receive urgent pointer */ 445067Swnj tcp_seq irs; /* initial receive sequence number */ 455067Swnj /* 465067Swnj * Additional variables for this implementation. 475067Swnj */ 485076Swnj /* receive variables */ 495076Swnj tcp_seq rcv_adv; /* advertised window */ 505067Swnj /* retransmit variables */ 515092Swnj tcp_seq snd_max; /* highest sequence number sent 525076Swnj used to recognize retransmits */ 535166Swnj /* transmit timing stuff */ 545166Swnj short t_idle; /* inactivity time */ 555166Swnj short t_rtt; /* round trip time */ 565166Swnj tcp_seq t_rtseq; /* sequence number being timed */ 575166Swnj float t_srtt; /* smoothed round-trip time */ 585067Swnj }; 594808Swnj 604881Swnj #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 614881Swnj #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 624881Swnj 634926Swnj struct tcpstat { 644926Swnj int tcps_badsum; 654926Swnj int tcps_badoff; 664926Swnj int tcps_hdrops; 674926Swnj int tcps_badsegs; 684926Swnj int tcps_unack; 694926Swnj }; 704926Swnj 714808Swnj #ifdef KERNEL 725067Swnj struct inpcb tcb; /* head of queue of active tcpcb's */ 735067Swnj struct tcpstat tcpstat; /* tcp statistics */ 744881Swnj struct tcpiphdr *tcp_template(); 754808Swnj #endif 76